1. Field of the Invention
The present invention pertains to the field of laser range finding devices for measuring the distance between the device and a remote object or surface. In particular, the present invention pertains to portable, hand-held distance-measurement devices.
2. Background Information
There are several prior art distance-measurement systems that have utilized a laser range finder. These systems generally transmit a beam of light energy, receive a reflection of the light beam, and measure the difference in time between the transmission and reception of the light beam.
Most laser range finding systems utilize a high-speed clock to count the time lapse between the transmission and reception of light pulses. High-speed clocks and other high-speed components required to implement such a technique consume too much electrical energy for practical use in a portable, battery-operated range finder. Most of the prior art range finder systems cannot operate for an adequate period of time using conventional batteries that are small enough for truly portable use.
In addition, most of the prior art distance-measurement systems require that the light beam from the range finder be incident on the intended target for a specified minimum period of time. If the user of the range finder even slightly moves the range finder so that the light beam no longer contacts the intended target, the measurements obtained by the range finder are generally inaccurate. Thus, most distance-measurement systems require that the range finder be mounted on a steady and secure surface, which prevents their use in an application that calls for a hand-held device.